Waste to Energy Technology
June 2011
Author: Jake Jacobi
Contact: Chris Vlahoplus
Copyright © 2011 by ScottMadden. All rights reserved.
Table of Contents
 What is WTE Technology?
 Municipal Solid Waste: Supply, Process, Sustainability, Technology
 Landfill Gas Process Flows and Methane Emissions
 WTE in the U.S. and Around the World
 Government Policies and Regulations
 Opposition to WTE
 How ScottMadden Can Help
Copyright © 2011 by ScottMadden. All rights reserved.
1
Waste-to-Energy:
What is WTE Technology?
Waste-to-Energy (WTE) technology utilizes Municipal Solid Waste (MSW) to create electric and heat energy through
various complex conversion methods
 WTE technology provides an alternative source of renewable energy in a world with limited or challenged fossil reserves
 MSW is considered a source of renewable energy because it contains a large amount of biological and renewable
materials
— There is a significant excess supply of MSW (primarily in landfills) around the globe
— The demand for MSW as a fuel source has increased
 The most common conversion method of MSW to energy is combustion and although it is currently entrenched in the
market, there are three emerging technologies moving toward the forefront
— Biological treatment method via anaerobic digestion: Anaerobic digestion is a waste-to-fuel application; waste can be
converted into purified biogas which can then be used to power gas engines or turbines to create heat or electricity.
The biogas can also be purified and compressed to be used as vehicle fuel
— Thermal treatment methods that yield energy in the form of heat and electricity include combustion, gasification, and
pyrolysis
— Pyrolysis used in the production of cellulosic ethanol – there are multiple facilities in the pilot and commercialization
stages
 Columbia University researchers assert that technology breakthroughs in recent years now make sending trash to landfills
a waste of energy
— The study, co-authored by researchers at the university's Earth Engineering Center, determined that if the U.S. took all
the non-recycled plastic currently sent to U.S. landfills each year and instead sent that trash to a waste-to-energy
(WTE) power plant, it would produce enough electricity for 5.2 million U.S. homes annually
— Some states are taking advantage of the latest waste management technology. Connecticut, for example, has the best
record for this, achieving a recovery of 65 percent on plastic waste when including both recycling and waste-to-energy
conversion
— Other states with the best record for capitalizing on the energy of waste include (in order) Massachusetts, Hawaii,
Maine, Virginia, Minnesota, New Jersey, New York, Maryland, and Pennsylvania
Source: Pike Research. “Waste-to-Energy Technology Markets,” Columbia University Report from April, 2011
Copyright © 2011 by ScottMadden. All rights reserved.
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Waste-to-Energy:
WTE Plant Diagram
Combustion is currently the primary method of converting waste to energy
Source: Ecomaine
Copyright © 2011 by ScottMadden. All rights reserved.
3
Municipal Solid Waste:
Supply of MSW for WTE
The feedstock for WTE is predominantly MSW, which at the present time is widely available around the world
 Over a billion tons of MSW is processed in landfills each year
— Growth rates of waste in most industrialized countries are comparable to GDP growth and energy consumption
— Despite plans of increased investment in WTE technology, 20-year projections indicate that MSW is a sustainable
feedstock supply
 Unlike most other biofuel inputs, using MSW feedstock for WTE is a low cost supply and can actually create a revenue
stream via tipping fees from landfill operators
— Landfill owners have a significant incentive to divert
MSW to alternative sites due to the high costs and time
involved in permitting additional landfill capacity
— In some cases it is not possible to permit new landfills or
expand existing landfill capacity
 MSW can be defined in different ways depending on the
nation or international organization involved; the definition
has significant effects on the WTE markets
— The quality and contents of MSW are dependent upon
the definition and the characteristics of the landfill
— The International Energy Agency (IEA) defines MSW
with regard to waste in WTE as household waste and
commercial and industrial waste that has a composition
similar that of household waste
Source: Pike Research. “Waste-to-Energy Technology Markets”
Copyright © 2011 by ScottMadden. All rights reserved.
4
Municipal Solid Waste:
The Waste-to-Energy Process
Waste is collected within a municipality, delivered to WTE facilities,
and converted into a form of usable energy
 In most developed countries, almost all waste that is generated is
collected by municipal or private services
— The International Energy Agency (IEA) states that “MSW is waste
typically collected and managed by local municipalities, i.e., it is
predominantly the waste generated by households and collected
from households or from areas to which households have access to
deposit their waste. It also includes wastes of a similar nature
derived from the commercial and industrial waste sector”
 MSW is transported by trucks with a capacity of multiple tons of MSW per trip - instead of being delivered to traditional landfills, a
percentage of landfill waste is diverted to WTE facilities
— The number of trucks visiting a plant each day and the distance the trucks must travel are dependent upon the size and location
of the plant
— Each WTE plant may have contracts with one or more waste collection companies to guarantee a set amount of daily waste
delivered
 Depending on the contract, waste haulers may pay a Tipping Fee to the WTE plant instead of paying a Gate Rate to a
landfill. Usually the plant will have to pay for the transportation costs of delivering to the plant instead of a closer landfill.
Other contracts may provide that the haulers will pay for transportation themselves but not pay the Tipping Fee
 These contracts may have provisions that WTE plants either earn revenues on hauling feedstock or receive feedstock
at no cost
 Depending on the conversion method, the waste may be pretreated for conversion through a process of inspecting and sorting,
which is an added cost to the facility
Source: ScottMadden research
Copyright © 2011 by ScottMadden. All rights reserved.
5
Municipal Solid Waste:
Sustainability of MSW as a WTE Feedstock
Feedstock supply for MSW must be analyzed to ensure a sustainable long-term supply, but feedstock supply risks can be
mitigated through long-term multiple contracts between the suppliers and the WTE facility
 MSW availability is driven by three variables: population, diversion, and the economy
— Projected MSW availability is calculated as the population multiplied by the MSW per capita
— Recycling is currently the only diversion to pose a potential threat to MSW availability, but even in states with aggressive
recycling programs, MSW landfill capacity is only modestly lowered
 Future population and MSW diversion numbers are used to calculate long-term availability of MSW as a feedstock
 Ranges of feedstock availability and cost are developed through scenario analysis of population, the economy, landfill capacity
projections and by determining if there are other users of MSW for landfills targeted as feedstock sources for a particular project
Source: ScottMadden research
Copyright © 2011 by ScottMadden. All rights reserved.
6
Municipal Solid Waste:
MSW as a Source of Energy
In 2007, MSW made up about 0.4% of the world’s energy mix. As investment in renewable sources of energy increases,
investment in WTE and the percentage of MSW as a global provider of energy will increase as well
 As of 2010, 86 plants operate in 24 states in the U.S. and have capacity to process more than 97,000 tons of municipal solid waste
per day
 Although the WTE 2010 electric generating capacity is only around 250 MW, there is also the production of process steam in
cogeneration plants
Source: Pike Research,
Copyright © 2011 by ScottMadden. All rights reserved.
7
Municipal Solid Waste:
Conversion Technologies
There are multiple technologies for converting MSW to energy, but these technologies are not in competition with each other
 Incineration of waste is the most prevalent form of converting MSW to energy. The waste is combusted, and the heat or biogas
created is harnessed and either distributed as heat or converted into another form of useful energy –steam or electricity
 Combustion processes are classified as mass
burn combustion, where waste is not pre-sorted,
or RDF combustion, a more costly process
where recyclable materials are sorted from the
rest of the waste. This process is also known as
the Solid Recovered Fuel (SRF) combustion
process
 Another thermal treatment process is
gasification, which is effective in minimizing air
pollutants. Gasification occurs in the presence
of limited oxygen and generates a synthetic gas
to be used in a heat and electricity producing
gas turbine
 A third process, pyrolysis, is now reaching
market maturity - it is a thermochemical process
that produces syngas, and most recently
cellulosic ethanol
 Anaerobic digestion is a form of biological
treatment where organic material is treated and
the output biogas is rich in methane. The biogas
can be cleaned and used, turned into heat and
electricity, or used for methane
Source: Pike Research. “Waste-to-Energy Technology Markets”
Copyright © 2011 by ScottMadden. All rights reserved.
8
Municipal Solid Waste:
MSW Treatment Through Gasification and Pyrolysis
Gasification and pyrolysis are types of thermal treatments used to convert MSW to energy
 Gasification is a process that uses high temperatures (without combustion) to decompose materials to produce synthetic gas
— Synthetic gas, or syngas, is generally used to power gas engines or turbines to generate heat or electricity, but can also be
used as a fuel itself or as an intermediate in producing other fuels and chemicals
 Using syngas to generate heat or electricity is more efficient than combusting MSW
 Syngas can be used to produce synthetic diesel - this liquid form of syngas is cleaner and more efficient than many
alternative liquid fuels
— When compared to a WTE combustion process, gasification significantly reduces air emissions and produces a product with
a higher thermal efficiency
Source: ScottMadden research
Copyright © 2011 by ScottMadden. All rights reserved.
9
Municipal Solid Waste:
MSW Treatment Through Gasification and Pyrolysis (Cont’d)
Pyrolysis has been demonstrated at pilot and small commercial scale – advancement to large scale could be a game changer
 Pyrolysis is an advanced form of gasification that chemically decomposes organic materials by heat in the absence of oxygen.
The process typically occurs under pressure and at very high operating temperatures – around 500 degrees Celsius
— Bio-oil, a gas, and char are the products of the
pyrolysis process
 Bio-oil is a purified, liquid renewable
energy source which can be used to
produce power and heat for industrial
boilers
— Pyrolysis as WTE technology has been piloted
and is beginning to be tested in the markets
— Pyrolysis is also reaching commercialization in
the production of cellulosic ethanol
Source: Pike Research. “Waste-to-Energy Technology Markets”
Copyright © 2011 by ScottMadden. All rights reserved.
10
Municipal Solid Waste:
Anaerobic Digestion
Anaerobic digestion (AD) is the only form of biological treatment of MSW. It creates the least amount of waste and is the
most efficient conversion technology, yet has the smallest contribution to total energy output of WTE
 Anaerobic digestion produces a biogas which can be used to produce electricity, process steam, or in the transportation sector
— In this biological process, microorganisms are used to break down organic waste in the absence of oxygen in an enclosed
vessel. Temperature, moisture, nutrient contents, and pH of the organic matter are key factors in the process
— The biogas from AD consists of 60%-70% methane (CH4), 30%-40% carbon dioxide (CO2), and other trace chemicals
 Biogas can be used to power a gas engine or turbine or it can be compressed and purified for use as vehicle fuel
 Methane may also be extracted from the biogas for direct use
 Many forms of anaerobic digestion exist and some of these are more efficient than others. Efficiency of the AD process
depends on the form of waste used as feedstock as well as the vessel used to host the process
— Until recently, AD adopters have been individual farms looking for ways to reduce their environmental (waste) footprint and
thus have been focused less on economics than other non-financial factors
 In these cases, the main feedstock for AD has been animal waste as opposed to MSW
— Municipal sewage contains biomass solids, so AD is also used in wastewater treatment plants to reduce volume of those
solids. However, AD of sewage produces other harmful chemicals not found in AD of farm animal waste
— Landfill gas (LFG)-to-energy is a less efficient form of AD that harnesses and uses gas from pre-existing landfills
 Two drawbacks of AD are its by-product and its need to be pre-treated
— In addition to the methane-rich biogas created in the AD process, a digestate, in either a solid or liquid form (depending on
either dry or wet input) is also created as a by-product. The digestate must be disposed of or composted in solid form or
purified and treated in its liquid form. This treatment process requires expensive, complex technologies
— In order for MSW to be used in this process, it must be inspected and sorted to remove plastics and other contaminants.
This added cost reduces the efficiency of AD
Source: Pike Research. “Waste-to-Energy Technology Markets;” ScottMadden. “Anaerobic Digestion: Farm Waste” Final Draft
Copyright © 2011 by ScottMadden. All rights reserved.
11
Municipal Solid Waste:
Anaerobic Digestion (Cont’d)
Landfill gas technology is proven commercially
 Landfill gas (LFG)-to-energy is a form of anaerobic digestion and is a biological treatment method of WTE. LFG-to-energy has
existed and has proven successful for many years. Since the 1970’s, landfills in the U.S. have collected LFG for conversion to
useful energy
— LFG is created during the decomposition of organic substances in MSW when it is dumped, compacted, and covered
 Gas formation is influenced by a number of factors such as the landfill material, the storage height and density of
the landfill material, water content, air temperature, atmospheric pressure and precipitation levels
— LFG-to-energy as a method of WTE conversion does not require new technology, but instead depends on harnessing the
methane (CH4), carbon dioxide (CO2), and nitrogen (N2) that is and always has been created by MSW
 LFG-to-energy is economically attractive because unlike other WTE conversion technologies, it does not require a
new facility. Gas can be collected from an existing landfill and either used as is, upgraded to a higher quality gas,
or converted to energy through combustion, a gas turbine, or a steam turbine
– Existing landfills may already have gas collection systems in place, and adding a power plant requires
minimal capital investment
— Direct use of LFG or gas-to-power projects are the most viable for LFG-to-energy; upgrading LFG to a high-BTU pipeline gas
is not cost effective for most plants
 Piping the medium-BTU LFG directly to nearby gas customers for boiler or industrial is the most efficient use of
LFG, however, this method requires nearby demand of a lower BTU value gas
 Converting gas to electricity with combustion engines or turbines allows the plant to use or sell generated electricity
— The finite number of existing landfills and their limited capacities are the leading drawbacks for investing in this technology
 Few landfills are thought to recover more than 60% of available LFG even with well-designed systems
 The decomposition process in a landfill providing gas with sufficient methane content lasts approximately 15 to 25
years, with the gas volume decreasing continuously over the years, once landfilling concludes
 EPA has already identified the potential sites for LFG utilization, and market competition is already well-established
Source: ScottMadden research
Copyright © 2011 by ScottMadden. All rights reserved.
12
Landfill Gas Process Flows
Example Landfill Gas Extraction Layout with Active Gas Collection
Landfill site
Gas well
Gas flare
Landfill gas main line
Blower
Exhaust gas
Dump radiator
Electrical
energy
 Perforated tubes are drilled into the landfill body and interconnected by a pipework system. Utilizing a blower, the gas is sucked
from the landfill, compressed, dried and fed into the gas engine
 For safety reasons, the installation of a gas flare is recommended so that excess gas can be burned off in the event of
excessive gas production
 In most cases, the electrical power generated is fed into the public grid
Source: GE Energy
Copyright © 2011 by ScottMadden. All rights reserved.
13
Electric Generation Technology Trends for LFG
The most prevalent technology for electricity production from LFG is the reciprocation engine, although other
technologies are utilized, depending on the size of the LFG well
 As of July 2011, there are 558 operational LFG energy projects in the United States and approximately 510 landfills that are good
candidates for projects
Source: EPA
Copyright © 2011 by ScottMadden. All rights reserved.
14
Methane Emissions from Landfills
Landfill gas methane exists in significant concentrations throughout the U.S.
Source: NREL
Copyright © 2011 by ScottMadden. All rights reserved.
15
WTE in the U.S. and Around the World:
Current State of WTE
Over the last 15 years, the United States has been lagging in the WTE market - Western Europe and Asia Pacific have had
the most exposure to the market
 There are currently over 900 WTE plants in operation around the globe producing over 130 terawatt hours (TWh) of electricity
from an estimated 0.2 billion tons of MSW
 There are several factors that could drive WTE technology growth in the U.S.
— Demand for energy-from-waste will depend on conversion efficiencies, and also on the inability for new landfills to be
expanded, or new landfills to be constructed
— Several government initiatives encourage domestic growth of WTE technology as a source of renewable energy
 Tax credits, subsidies, GHG emissions restrictions, and renewable energy legislation are a few existing and
potential initiatives
 The market for WTE technology in the European Union (EU) varies significantly by country
— In 2009, nearly 400 European plants produced over 30 TWh of electric and 55 TWh of heat, enough to power 8 million
households
— The Scandinavian countries and Germany have invested significant resources to WTE technology and are leading the EU
 WTE in the Asia Pacific region is made up mostly of China and Japan. Combined, those nations generate nearly half of all WTE
revenue in the world. It is expected that the Asia Pacific region will continue to lead in WTE development through the decade
 The use of WTE technology for island nations is perhaps even more significant. The combinations of an abundance of seawater
and a lack of fresh water and landfill space provides a perfect implementation scenario for a WTE plant
— By using MSW to generate electricity, island nations can prevent the need for future landfilling, and also provide cheap
energy to power desalination plants. Desalination can be accomplished through reverse osmosis, powered by electricity, or
through a thermal desalination process powered by heat energy
Copyright © 2011 by ScottMadden. All rights reserved.
16
WTE in the U.S. and Around the World:
WTE Projected Revenue in the World Markets
WTE revenue is projected to grow over the next five years in the Asia Pacific region
Source: Pike Research. “Waste-to-Energy Technology Markets”
Copyright © 2011 by ScottMadden. All rights reserved.
17
WTE in the U.S. and Around the World:
Increased Capacity and Future Growth of WTE
A range of factors will drive the demand for WTE technology through the next decade and beyond. The graph shows the
realistic (R) and potential (P) output from thermal treatment of MSW through 2020
 Global demand for energy is projected to
rise, especially in developing nations
Thermal Treatment MSW, Total Energy Output, EU-27: 2006-2020
 Global supply of MSW will continue to
grow in line with GDP. Only a few
countries around the world have been
able to reduce MSW compared to GDP
 The world’s non-renewable fuel sources
are being depleted
— Uncertainty of future availability of
energy will likely lead to investment in
alternative energy sources
 Governments are imposing policies and
regulations to promote development of
renewable energy technology and to
reduce GHG emissions
 Proper investment in WTE technology
has the potential to generate significant
revenues in many parts of the world
Source: Pike Research. “Waste-to-Energy Technology Markets,” ScottMadden research
Copyright © 2011 by ScottMadden. All rights reserved.
18
Government Policies and Regulations on WTE Market
As with most renewables, incentives and governmental intervention are key growth drivers
 Due to the many negative effects of landfills, some governments are implementing landfill taxes, while others are banning
landfills altogether
— In the U.S. in the 1990’s, the EPA enacted stricter air emissions standards on incinerators. This not only required WTE
plants to reduce air pollution, but also reduced non-WTE incineration
 New incineration regulations also led to higher standards of disposal of ash and residue from WTE plants
— The EU Landfill Directive limits the disposal of biodegradable waste in landfills
— Landfill taxes encourage the use of WTE by increasing the cost of simply dumping waste
 Due to recent awareness of global climate change, many governments have enacted policies regarding the release of green
house gas (GHG) emissions into the environment
— With regard to waste management, the Intergovernmental Pane on Climate Change (IPCC) recognizes WTE as a GHG
emissions reduction process
— According to IPCC projections, increased capacity of WTE plants could reduce emissions by 90 million tons CO2 equivalent
by 2020
 Many policies that promote investment in renewable energy technologies, including WTE technology, have been put into place
— Federal government tax credits, stimulation packages, subsidies, etc. are awarded to both the private and public sector for
WTE investment
 Policies and taxes have been enacted in order to decrease our dependence on fossil fuels for energy
ScottMadden research, IPCC reports
Copyright © 2011 by ScottMadden. All rights reserved.
19
How ScottMadden Can Help
 ScottMadden has experience in the WTE area:
— We have evaluated Department of Energy projects for MSW feedstocks
— We have performed detailed MSW feedstock (landfill) sustainability assessments
— We understand the WTE value chain and all technologies within the value chain
— We understand the WTE value chain including the markets and the technologies
 ScottMadden can provide assistance in the following areas:
— Performing project due diligence
— Assisting in development of an WTE strategy
— Performing a feedstock analysis (Feedstock sustainability and costs)
Copyright © 2011 by ScottMadden. All rights reserved.
20
Contact Us
For more information on Waste to Energy, please contact us.
Chris Vlahoplus
Partner and Clean Tech &
Sustainability Practice Leader
ScottMadden, Inc.
2626 Glenwood Avenue
Suite 480
Raleigh, NC 27608
Phone: 919-781-4191
chrisv@scottmadden.com
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